mirror of https://github.com/golang/go.git
102 lines
2.8 KiB
Go
102 lines
2.8 KiB
Go
// Copyright 2022 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package compare
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import (
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"cmd/compile/internal/base"
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"cmd/compile/internal/typecheck"
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"cmd/compile/internal/types"
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"cmd/internal/obj"
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"cmd/internal/src"
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"cmd/internal/sys"
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"testing"
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)
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type typefn func() *types.Type
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func init() {
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// These are the few constants that need to be initialized in order to use
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// the types package without using the typecheck package by calling
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// typecheck.InitUniverse() (the normal way to initialize the types package).
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types.PtrSize = 8
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types.RegSize = 8
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types.MaxWidth = 1 << 50
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base.Ctxt = &obj.Link{Arch: &obj.LinkArch{Arch: &sys.Arch{Alignment: 1, CanMergeLoads: true}}}
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typecheck.InitUniverse()
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}
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func TestEqStructCost(t *testing.T) {
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repeat := func(n int, typ *types.Type) []*types.Type {
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typs := make([]*types.Type, n)
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for i := range typs {
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typs[i] = typ
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}
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return typs
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}
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tt := []struct {
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name string
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cost int64
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nonMergeLoadCost int64
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fieldTypes []*types.Type
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}{
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{"struct without fields", 0, 0, nil},
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{"struct with 1 byte field", 1, 1, repeat(1, types.ByteType)},
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{"struct with 8 byte fields", 1, 8, repeat(8, types.ByteType)},
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{"struct with 16 byte fields", 2, 16, repeat(16, types.ByteType)},
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{"struct with 32 byte fields", 4, 32, repeat(32, types.ByteType)},
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{"struct with 2 int32 fields", 1, 2, repeat(2, types.Types[types.TINT32])},
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{"struct with 2 int32 fields and 1 int64", 2, 3,
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[]*types.Type{
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types.Types[types.TINT32],
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types.Types[types.TINT32],
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types.Types[types.TINT64],
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},
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},
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{"struct with 1 int field and 1 string", 3, 3,
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[]*types.Type{
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types.Types[types.TINT64],
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types.Types[types.TSTRING],
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},
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},
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{"struct with 2 strings", 4, 4, repeat(2, types.Types[types.TSTRING])},
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{"struct with 1 large byte array field", 26, 101,
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[]*types.Type{
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types.NewArray(types.Types[types.TUINT16], 101),
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},
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},
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{"struct with string array field", 4, 4,
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[]*types.Type{
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types.NewArray(types.Types[types.TSTRING], 2),
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},
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},
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}
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for _, tc := range tt {
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t.Run(tc.name, func(t *testing.T) {
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fields := make([]*types.Field, len(tc.fieldTypes))
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for i, ftyp := range tc.fieldTypes {
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fields[i] = types.NewField(src.NoXPos, typecheck.LookupNum("f", i), ftyp)
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}
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typ := types.NewStruct(fields)
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types.CalcSize(typ)
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want := tc.cost
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base.Ctxt.Arch.CanMergeLoads = true
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actual := EqStructCost(typ)
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if actual != want {
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t.Errorf("CanMergeLoads=true EqStructCost(%v) = %d, want %d", typ, actual, want)
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}
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base.Ctxt.Arch.CanMergeLoads = false
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want = tc.nonMergeLoadCost
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actual = EqStructCost(typ)
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if actual != want {
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t.Errorf("CanMergeLoads=false EqStructCost(%v) = %d, want %d", typ, actual, want)
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}
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})
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}
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}
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